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1.
Xiaoqian Li Zhiyou Guo Yang Li Peng Zhou Xuhui Chen Zhenyu Li Xiaoguo Xiang 《Nordic Journal of Botany》2019,37(12)
The taxonomic problem of cryptic species has long been recognized. Hemiboea subcapitata C. B. Clarke is a widespread and morphologically diverse species including two varieties, H. subcapitata var. subcapitata C. B. Clarke and H. subcapitata var. guangdongensis (Z. Y. Li) Z. Y. Li. However, genetic distance and molecular phylogenetic analyses based on nuclear ITS and four plastid DNA sequences (atpB‐rbcL, matK, rbcL, rpS16 intron) revealed that H. subcapitata var. guangdongensis is sister to H. subacaulis, and separated from H. subcapitata var. subcapitata, suggesting that it should be raised to the rank of an independent species as H. guangdongensis (Z. Y. Li) X. Q. Li & X. G. Xiang, comb. & stat. nov. Morphologically, the new species can be distinguished from H. subacaulis by its calyx 5‐sect from base, segments narrowly oblong‐lanceolate (versus calyx 5‐sect from base or 2‐lipped and adaxial lip 2‐lobed from below middle, segments ovate), peduncle glabrous (versus pubescent), and vermiform sclereids dispersed in leaf mesophyll (versus without sclereids). 相似文献
2.
Arabidopsis trichomes are an excellent cell type to address many questions in plant biology including the control of cell shape, endoreplication, and cell expansion. Because trichomes comprise such a small percentage of the cells of a leaf, biochemical analyses of trichomes are limited. To overcome this limitation, we developed a method for removing trichomes from the leaf surface. Our method allows the isolation of intact trichomes for use in downstream applications such as cell wall analysis, immunolocalization of trichome proteins, analysis of DNA content, and proteomics. Also, this method will facilitate the isolation of trichomes from practically any plant species. 相似文献
3.
Agoston GE Shah JH Lavallee TM Zhan X Pribluda VS Treston AM 《Bioorganic & medicinal chemistry》2007,15(24):7524-7537
A series of 16-modified 2-methoxyestradiol analogs were synthesized and evaluated for antiproliferative activity toward HUVEC and MDA-MB-231 cells, and for susceptibility to conjugation. In addition, the estrogenicity of these analogs was accessed by measuring cell proliferation of the estrogen-dependent cell line MCF7 in response to compound treatment. It was observed that antiproliferative activity dropped as the size of the 16 substituent increased. Selected analogs tested in glucuronidation assays had similar rates of clearance to 2-methoxyestradiol, but had enhanced clearance in sulfonate conjugation assays. 相似文献
4.
The proper control of cell expansion is vital to plant development. It is responsible for shaping individual cells and, together with cell division, it plays a lead role in shaping plant organs. Much of the underlying mechanism by which plant cells expand anisotropically is not understood. We are taking a genetic approach to cell expansion by isolating mutants that affect the branching pattern of Arabidopsis trichomes. Here we report the identification of four new loci that control trichome morphogenesis. These loci were named the IRREGULAR TRICHOME BRANCH (ITB) loci because of the deleterious effects on branch position and length in the mutants. Our analysis of branch expansion in itb mutants shows that the ITB genes act as positive regulators of branch elongation, and that the branch position defects are caused by altered expansion of the trichome stalk. The itb mutations display synergistic effects in double mutant combinations with certain branch number mutations, suggesting that the ITB genes also play key roles in branch initiation. These results demonstrate that the ITB genes are key regulators of anisotropic cell expansion in trichomes. 相似文献
5.
Factors affecting population dynamics of maternally transmitted endosymbionts in Bemisia tabaci 总被引:2,自引:0,他引:2
While every individual of Bemisia tabaci (Hemiptera: Aleyrodidae) harbors the primary symbiont (P-symbiont) Portiera, the infection frequencies of the six secondary symbionts (S-symbionts) including Hamiltonella, Arsenophonus, Cardinium, Wolbachia, Rickettsia and Fritschea vary greatly among different populations. To characterize the factors influencing the infection dynamics of the six S-symbionts in B. tabaci, gene-specific PCR were conducted to screen for the presence of the P-symbiont Portiera and the six S-symbionts in 61 (17 B and 44 Q biotypes) field populations collected from different plant species and locations in China. All individuals of the 61 populations hosted the P-symbiont Portiera, but none of them harbored Arsenophonus and Fritschea. The presence and infection rates of Hamiltonella, Cardinium, Rickettsia, Wolbachia and their co-infections Rickettsia + Hamiltonella (RH), Rickettsia + Cardinium (RC), Hamiltonella + Cardinium (HC) and Rickettsia + Hamiltonella + Cardinium (RHC) varied significantly among the 61 field populations; and the observed variations can be explained by biotypes, sexes, host plants and geographical locations of these field populations. Taken together, at least three factors including biotype, host plant and geographical location affect the infection dynamics of S-symbionts in B. tabaci. 相似文献
6.
Xiaoguo Zhang Michelle Facette John A. Humphries Zhouxin Shen Yeri Park Dena Sutimantanapi Anne W. Sylvester Steven P. Briggs Laurie G. Smith 《The Plant cell》2012,24(11):4577-4589
Mechanisms governing the polarization of plant cell division are poorly understood. Previously, we identified pangloss1 (PAN1) as a leucine-rich repeat–receptor-like kinase (LRR-RLK) that promotes the polarization of subsidiary mother cell (SMC) divisions toward the adjacent guard mother cell (GMC) during stomatal development in maize (Zea mays). Here, we identify pangloss2 (PAN2) as a second LRR-RLK promoting SMC polarization. Quantitative proteomic analysis identified a PAN2 candidate by its depletion from membranes of pan2 single and pan1;pan2 double mutants. Genetic mapping and sequencing of mutant alleles confirmed the identity of this protein as PAN2. Like PAN1, PAN2 has a catalytically inactive kinase domain and accumulates in SMCs at sites of GMC contact before nuclear polarization. The timing of polarized PAN1 and PAN2 localization is very similar, but PAN2 acts upstream because it is required for polarized accumulation of PAN1 but is independent of PAN1 for its own localization. We find no evidence that PAN2 recruits PAN1 to the GMC contact site via a direct or indirect physical interaction, but PAN2 interacts with itself. Together, these results place PAN2 at the top of a cascade of events promoting the polarization of SMC divisions, potentially functioning to perceive or amplify GMC-derived polarizing cues. 相似文献
7.
Difference in feeding behaviors of two invasive whiteflies on host plants with different suitability: implication for competitive displacement 总被引:5,自引:0,他引:5
Liu B Yan F Chu D Pan H Jiao X Xie W Wu Q Wang S Xu B Zhou X Zhang Y 《International journal of biological sciences》2012,8(5):697-706
In China, Bemisia tabaci Q (commonly known as biotype Q) has rapidly displaced B (commonly known as biotype B) in the past 6 years. The mechanisms underlying such phenomenon have been studied extensively in recent years; however, we have not come to a definitive conclusion yet. In the present study, the differences in host suitability between B and Q whitefly adults to five host plants (cabbage, cotton, cucumber, poinsettia, and tomato) were evaluated based on their respective feeding behaviors using a direct-current electrical penetration graph (DC-EPG) system. Pair-wise comparisons of B. tabaci B and Q feeding on each of the five host plants clearly indicate that Q feeds better than B on tomato, cotton and poinsettia, while B feeds better than Q on cabbage and cucumber. The EPG parameters related to both phloem and non-phloem phases confirm that cabbage and cucumber are best suited to B, while tomato, cotton, and poinsettia are best suited to Q. Our present results support the contention that host suitability and adult feeding behavior contribute to the competitive displacement of biotype B by biotype Q. The discrepancy between field (previous studies) and laboratory results (this study), however, suggests that 1) whitefly displacement is apparently contributed by multiple factors; and 2) factor(s) other than the host plant suitability may play a vital role in dictating the whitefly biotypes in the field. 相似文献
8.
乳清蛋白是牛乳中一类营养价值较高的优质蛋白,必需氨基酸种类齐全,组成模式与人体相似,并含有丰富的支链氨基酸和多种生物活性物质,能够提高机体的抗氧化能力,增强机体免疫力,促进骨骼肌蛋白质的合成,抑制肌肉蛋白分解,加速训练后体能的恢复,对于运动人群而言,是补充优质蛋白的良好来源.本文就合理的补充乳清蛋白对缓解运动性疲劳、提高运动能力的研究进展进行了综述. 相似文献
9.
Host‐induced gene silencing of an important pathogenicity factor PsCPK1 in Puccinia striiformis f. sp. tritici enhances resistance of wheat to stripe rust
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Tuo Qi Xiaoguo Zhu Chenlong Tan Peng Liu Jia Guo Zhensheng Kang Jun Guo 《Plant biotechnology journal》2018,16(3):797-807
Rust fungi are devastating plant pathogens and cause a large economic impact on wheat production worldwide. To overcome this rapid loss of resistance in varieties, we generated stable transgenic wheat plants expressing short interfering RNAs (siRNAs) targeting potentially vital genes of Puccinia striiformis f. sp. tritici (Pst). Protein kinase A (PKA) has been proved to play important roles in regulating the virulence of phytopathogenic fungi. PsCPK1, a PKA catalytic subunit gene from Pst, is highly induced at the early infection stage of Pst. The instantaneous silencing of PsCPK1 by barley stripe mosaic virus (BSMV)‐mediated host‐induced gene silencing (HIGS) results in a significant reduction in the length of infection hyphae and disease phenotype. These results indicate that PsCPK1 is an important pathogenicity factor by regulating Pst growth and development. Two transgenic lines expressing the RNA interference (RNAi) construct in a normally susceptible wheat cultivar displayed high levels of stable and consistent resistance to Pst throughout the T3 to T4 generations. The presence of the interfering RNAs in transgenic wheat plants was confirmed by northern blotting, and these RNAs were found to efficiently down‐regulate PsCPK1 expression in wheat. This study addresses important aspects for the development of fungal‐derived resistance through the expression of silencing constructs in host plants as a powerful strategy to control cereal rust diseases. 相似文献
10.
<正>1常用植物DNA条形码物种的准确鉴定是开展科学研究和生物多样性保护的先决条件,但根据形态学特征进行物种鉴定对非专业人员而言比较困难。即使是专业人员,面对纷繁复杂的物种,要想逐一鉴定也难以实现。DNA条形码技术(DNA barcoding)为物种的快速、准确鉴定提供了可能(Hebert et al.,2003)。线粒体COI基因作为动物的DNA条形码已得到广泛应用。但对 相似文献